Maybe you could also "reduce" the bit in a different way, where it would be 50/50 if a message would actually be sent upon clicking the submit/reply button.

Like if you'd walk on a noisy street, see someone you know, and greet them half-heartedly and wouldn't really mind if they didn't hear you.

Oh man, the thrill of not knowing if this message will actually be sent when I hit the "reply" button!